Safety glass composition



&m 9, 334& e. BARSKY 29335953@ SAFETY GLASS COMPOSITIO&

Filed Jan. 28, 1942 IN VENT OR. Geo/'ga day/'sky Patented Oct. 9, 1945 smarr GLASS COMPOSITION I George Bau-sky, New York, N. Y., assignor to Wecoline Products, Inc., Boonton, N. J., a corporation of New Jersey Application January 28, '1942, Serial No. 428503' 6 Claims; (CI. zoo-36) The present invention is directed to' plastic compositions particularly adapted for use in the production of safety glass which consists essentially of two sheets of glass held together by an intermediate film of a plastic material. More particularly, the present invention relates to improvements in the plastic material used in making the safety glass.

Various thermoplastic compounds have heretofore been used as the intermediate layer of safety glass and it has been found necessary to add to such substances suitable plasticizing materials which impart to the composition certain essential properties. A considerable number of plasticizers in synthetic and other plastic compositions have been known, but very few of these are applicable for the present purpose. For instance, there has been proposed the' use of the higher i'atty acid esters of certain glycols as plasticizers for nitrocellulose. such products are of some value in nitrocellulose compositions, but 'only to a limited extent. ,since the amount of this -plasticizer which can be used in the composition is quite small, it does not exert a'suflicient plasticizing efl'ect. If a moderate amount thereof is added, thenthe composition has a frosty appearance due to the separating-out of theplasticizer. This would-render a composition of this character incapable of use in safety glass.

. Another' composition previously used consisted in the ethylene glycol esters of low m'olec-ular weight fatty' acids such as those having 8 or 10 carbon atoms. Plasticizers of this type have been successfully used in compositions for making' safety glass since they are capable of blending in wide proportions with the synthetic materials,

' present invention to provide a plasticizing material which is simple to produce, which is low in cost, and wherein the raw materials for the production thereof are 'readily available.

In practicing the present invention I provide an ester which is the tri-ethylene glycol ester of 'they are non-volatile, are water resistant, and do i i to the molecule.

fatty acids having from 6 to 18 carbon atoms. V

An ester of this type is subjected to treatment with a halogen, usually chlorine, under such conditions as to add a substantial amount of chlorine Where the fatty acid inthe ester is unsaturated, the chlorination takes place to at least the point where the iodine number has become practically negligible, and a higher degree of chlorination may be obtained. In other words, the chlorination is conducted at least until the double b'onds have been saturated. Where a saturated acid is employed, the chlorination is-conducted until there has been a' substa'ntia-l displacement of hydrogen by chlorine.

The following is an example of the operation of the present invention:

Ina suitable reaction vessel there is placed a. desired amount of tri-ethylene glycol oleate having a saponification number of 173, an iodine number of 70.6 and a density at 24 C. of 0.924. The reaction vessel .is subjected to cooling by immersing the same in circulating cold water. Chlorine is bubbled slowly through the ester with constant stirring, the circulation of water being conducted so as -to maintain a temperature in the reaction vessel between 20 and 25 C.

As the reaction proceeds the color of the ester becomes darker and after a suflicient time it becomes lighter again, indicating the approximate end of the operation. Chlorine is allowed to bubble through` the mass for about an additional 10 minutes. Thereafter, carbon' dioxide is bubbled through the chlorinated ester to remove free chlorine, and the flow of carbon dioxide is continued until a test of the product with starchiodide paper, gives a negative indication for chlorine. The resulting product has a density of 1.14 at 30 C. and has an iodinenumber of 0.3. I

. A plastic composition is made with the abovedescribed chlorinated ester by providing a solution of a vinyl resin in a mixture of ethyl alcohol and ethyl lactate, the proportions thereof being portion of three parts of ester to Seven parts of resin. The solution is poured on a smooth .sheet of metal such as amalgamated tin, and the solvent is allowed to evaporate. The film is stripped chlorinatedester from the composition. It was also subiected to a temperature below -10 C. tor

a substantial length of time, without causing any cloudiness, crystallization or deterioration of the composition. Under all of the tests, the material remained clear and transparent. Upon being subjected to a shattering test, the safetv` siass proved to be highly effective.

In the accompanying drawing constitutlng a part hereof, 'the single figure is a iragmentary,

Instead o! pouring the conp ton as stated above, other methods or forming' the film may be adopted, as the hot rolling of the mass. The amount o! plasticizer used in the composition may be vai-led within wide limits, it being possible to incorporate as much as 50% thereof with good results. As little as 10% or the plasticizer will 'give a measurable and desirable eflect;

The essence oi the present invention is the halogenation oi! the compounds used. When certain unhalogenated esters are used, the safety siass is unsatistactory as shown by tests; by halosenatins the same, such esters are rendered suitable !or the cross-sectional view of `a piece of safety glass 4 made in accordance with the present invention- There is provided two sheets I and 2 of glass, and between the same is a. plastic layer I, which is transparent and which acts as a permanent bond for the sheets ofglass. Layer 3 consists essentially of a resinous material of the thei-moplastic type, having incorporated therein a plasticizr taken from the class consistin'g of the triethylene glycol esters of higher fatty acids, preferably those having from 6 to 18 carbon atom&

The esters are halogenated to a substantia degree, the halcgen being attached to the acid radical of the ester and not to the glycol radical. A composition which has been found suitable is a mixture oi a vinyl -esin with the tri-ethylene glycol ester of oleic acid, the latteradical having been chlorinated at least to the point of satura'- tion of the double bond.

Although the invention has been described with a single specific example, it will be apparent that various modificationsand changes may be made purpose. Certain other unhalogenated esters are satistactory, but after halogenation they become still more suitable in that the desirable characteristics thei-eo! have been improved. It, thereore, appears that the halogen imparts to the esters a marked adherence to the' siass and a compatibility which render the esters highly satisfactory for the purpose.

What is claimed is:

1. A plastic composition adapted for use in safety class comprising a resinous synthetic thermoplastic material taken from the class consisting of vinyl resins having incorporated therein a plasticizer taken from the class consisting oithe tri-ethyiene glycol esters of Iatty acids having from sto 18 carbon at'oms, saidesters being haloi genated to a substantial degree, the halogen being attached to the acid radical' oi said ester.

2. A plastic 'composition adapted !or use in safety glass comprising a resinous synthetic thermoplastic material which is the condensation product of polyvinyl alcohol and butraldehyde having incorporated' therein a plasticizer taken from the class consisting of the tri-ethylene glycol esters of i'atty acids'having !rom 6 to 18 carbon atom& said esters being halogenated to e. substan- 40 tial degree, the halogen being attached to the acid in the details thereof. For instance, various plastic substances may be used such as, cellulose nitrate, ethyl oellulose, poly-methyl acrylate, polyethyl acrylate, poly-methyl `xethacrylate, polyethyl methacrylate, poly-vinyl acetate, poly-vny products oi' the present invention have been found to be compatibile with such resinous materials, 'and the chlorinated esters may be incorpprated there in in widely varying proportions.

Other iatty acids may be substituted tor the oleic, such as, capric, lauric, myristic, linoleie and various others having from 6 to 18 carbon atoms. Also, t halogenation-may be conducted with fluorine oi' chlorir'e, but the latter is preferable since it is' more readily obtainable and easier t'o operate with. Also, hydrogenated fatty radical o! said ester, i

3. A plastic composition adapted tor use in safety siass comprising a Synthetic thermoplastic material which is the condensation product 'oi polyvinyl alcohol and butraldehyde, having incorporated therein the tri-ethylene glycol ester of oleic acid which is chlorinated to at least the chloracetate and the vinyl acetal resins. The

aci ds, such as ricinoleic or mixtures containing the'same, maybe used to give the halogenated esters. The presence of a hydroxy group in the ester improver` theproperties thereof for the de sired purpose Other glycols may be used, such .as the ethylene and propylene glycols, and mixtures containing. not only 'the'triethylene and the like glycols, but higher and lower aikylated com- 'poundsmaybeusei Mixturesoftwoormore fatti acidi! oi' the above-named group. may `be iedtogiveihemixedhalogenatedete's.-`

saturation of the double bond of said acid.

4. In resinous synthetic plastic materials, plesticizers whi'ch are the triethylene glycol esters oi' i i unsaturated !atty acidshaving from 8 to 18 carbon atoms, said ester-s beins -.halogenoted to a substantia degree, the halogenbeln ttached to the acid radiclofaid ester. i v

V :alone: nanes?. 

